diff --git a/htdocs/admin/agenda_extsites.php b/htdocs/admin/agenda_extsites.php
index 86701344ba4..83391e6ce3d 100644
--- a/htdocs/admin/agenda_extsites.php
+++ b/htdocs/admin/agenda_extsites.php
@@ -279,13 +279,13 @@ while ($i <= $MAXAGENDA) {
 	print '</td>';
 	// Calendar active by default
 	print '<td class="nowrap right">';
-	if ($conf->use_javascript_ajax) {
+	if (!empty($conf->use_javascript_ajax)) {
 		print ajax_constantonoff('AGENDA_EXT_ACTIVEBYDEFAULT' . $key);
 	} else {
-		if (empty($conf->global->{$default})) {
-			print '<a href="' . $_SERVER['PHP_SELF'] . '?action=set_AGENDA_EXT_ACTIVEBYDEFAULT' . $key . '&token='.newToken().'">' . img_picto($langs->trans("Enabled"), 'on') . '</a>';
-		} else {
+		if (getDolGlobalString($default)) {
 			print '<a href="' . $_SERVER['PHP_SELF'] . '?action=del_AGENDA_EXT_ACTIVEBYDEFAULT' . $key . '&token='.newToken().'">' . img_picto($langs->trans("Disabled"), 'off') . '</a>';
+		} else {
+			print '<a href="' . $_SERVER['PHP_SELF'] . '?action=set_AGENDA_EXT_ACTIVEBYDEFAULT' . $key . '&token='.newToken().'">' . img_picto($langs->trans("Enabled"), 'on') . '</a>';
 		}
 	}
 	print '</td>';
diff --git a/htdocs/comm/action/index.php b/htdocs/comm/action/index.php
index a6a39d1eb05..ab814957e5b 100644
--- a/htdocs/comm/action/index.php
+++ b/htdocs/comm/action/index.php
@@ -274,7 +274,7 @@ if (empty($conf->global->AGENDA_DISABLE_EXT)) {
 		$color = 'AGENDA_EXT_COLOR'.$i;
 		$default = 'AGENDA_EXT_ACTIVEBYDEFAULT'.$i;
 		$buggedfile = 'AGENDA_EXT_BUGGEDFILE'.$i;
-		if (!empty($conf->global->$source) && !empty($conf->global->$name)) {
+		if (getDolGlobalString($source) && getDolGlobalString($name)) {
 			// Note: $conf->global->buggedfile can be empty or 'uselocalandtznodaylight' or 'uselocalandtzdaylight'
 			$listofextcals[] = array(
 				'src' => getDolGlobalString($source),
@@ -299,14 +299,14 @@ if (empty($user->conf->AGENDA_DISABLE_EXT)) {
 		$enabled = 'AGENDA_EXT_ENABLED_'.$user->id.'_'.$i;
 		$default = 'AGENDA_EXT_ACTIVEBYDEFAULT_'.$user->id.'_'.$i;
 		$buggedfile = 'AGENDA_EXT_BUGGEDFILE_'.$user->id.'_'.$i;
-		if (!empty($user->conf->$source) && !empty($user->conf->$name)) {
+		if (getDolUserString($source) && getDolUserString($name)) {
 			// Note: $conf->global->buggedfile can be empty or 'uselocalandtznodaylight' or 'uselocalandtzdaylight'
 			$listofextcals[] = array(
-				'src' => $user->conf->$source,
-				'name' => dol_string_nohtmltag($user->conf->$name),
+				'src' => getDolUserString($source),
+				'name' => dol_string_nohtmltag(getDolUserString($name)),
 				'offsettz' => (int) (empty($user->conf->$offsettz) ? 0 : $user->conf->$offsettz),
-				'color' => dol_string_nohtmltag($user->conf->$color),
-				'default' => dol_string_nohtmltag($user->conf->$default),
+				'color' => dol_string_nohtmltag(getDolUserString($color)),
+				'default' => dol_string_nohtmltag(getDolUserString($default)),
 				'buggedfile' => dol_string_nohtmltag(isset($user->conf->buggedfile) ? $user->conf->buggedfile : '')
 			);
 		}
@@ -1287,7 +1287,7 @@ if (count($listofextcals)) {
 					}
 
 					// Transparency (see https://www.kanzaki.com/docs/ical/transp.html)
-					if ($icalevent['TRANSP']) {
+					if (!empty($icalevent['TRANSP'])) {
 						if ($icalevent['TRANSP'] == "TRANSPARENT") {
 							$event->transparency = 0; // 0 = available / free
 						}
diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 776633960e6..dbf3622f1a7 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -73,8 +73,9 @@ if (!function_exists('utf8_decode')) {
 
 /**
  * Return dolibarr global constant string value
- * @param string $key key to return value, return '' if not set
- * @param string $default value to return
+ *
+ * @param string $key 		key to return value, return '' if not set
+ * @param string $default 	value to return
  * @return string
  */
 function getDolGlobalString($key, $default = '')
@@ -86,8 +87,9 @@ function getDolGlobalString($key, $default = '')
 
 /**
  * Return dolibarr global constant int value
- * @param string $key key to return value, return 0 if not set
- * @param int $default value to return
+ *
+ * @param string 	$key 		key to return value, return 0 if not set
+ * @param int 		$default 	value to return
  * @return int
  */
 function getDolGlobalInt($key, $default = 0)
@@ -97,8 +99,37 @@ function getDolGlobalInt($key, $default = 0)
 	return (int) (empty($conf->global->$key) ? $default : $conf->global->$key);
 }
 
+/**
+ * Return dolibarr user constant string value
+ *
+ * @param string $key 		key to return value, return '' if not set
+ * @param string $default 	value to return
+ * @return string
+ */
+function getDolUserString($key, $default = '')
+{
+	global $user;
+	// return $conf->global->$key ?? $default;
+	return (string) (empty($user->conf->$key) ? $default : $user->conf->$key);
+}
+
+/**
+ * Return dolibarr user constant int value
+ *
+ * @param string 	$key 			key to return value, return 0 if not set
+ * @param int 		$default 		value to return
+ * @return int
+ */
+function getDolUserInt($key, $default = 0)
+{
+	global $user;
+	// return $conf->global->$key ?? $default;
+	return (int) (empty($user->conf->$key) ? $default : $user->conf->$key);
+}
+
 /**
  * Is Dolibarr module enabled
+ *
  * @param string $module module name to check
  * @return int
  */